This invention relates to the field of antibacterial treatments and to targets for antibacterial agents. In particular, it relates to genes essential for survival of a bacterial strain in vitro or in vivo.
The following background information is not admitted to be prior art to the pending claims, but is provided only to aid the understanding of the reader.
Despite the development of numerous antibacterial agents, bacterial infections continue as a major, and currently increasing, medical problem. Prior to the 1980s, bacterial infections in developed countries could be readily treated with available antibiotics. However, during the 1980s and 1990s, antibiotic resistant bacterial strains emerged and have become a major therapeutic problem. There are, in fact, strains resistant to essentially all of the commonly used antibacterial agents, which have been observed in the clinical setting, notably including strains of Staphylococcus aureus. The consequences of the increase in resistant strains include higher morbidity and mortality, longer patient hospitalization, and an increase in treatment costs. (B. Murray, 1994, New Engl. J. Med. 330:1229-1230.) Therefore, there is a pressing need for the development of new antibacterial agents which are not significantly affected by the existing bacterial resistance mechanisms.
Such development of new antibacterial agents can proceed by a variety of methods, but generally fall into at least two categories. The first is the traditional approach of screening for antibacterial agents without concern for the specific target.
The second approach involves the identification of new targets, and the subsequent screening of compounds to find antibacterial agents affecting those targets. Such screening can involve any of a variety of methods, including screening for inhibitors of the expression of a gene, or of the product of a gene, or of a pathway requiring that product. However, generally the actual target is a protein, the inhibition of which prevents the growth or pathogenesis of the bacterium. Such protein targets can be identified by identifying genes encoding proteins essential for bacterial growth.